SAS can detect several types of errors. Here are two common ones:

When you submit a program, SAS scans each statement for syntax errors, and then executes the step (if no syntax errors are found). SAS then goes to the next step and repeats the process. Syntax errors, such as misspelled keywords, generally prevent SAS from executing the step in which the error occurred.

Notes are written to the Log window when the program finishes executing. When a program that contains an error is submitted, messages about the error appear in the Log window. Here is what SAS does:

In the program below, the DATA step copies the SAS data set Clinic.Admit into a new data set named Clinic.Admitfee. The PROC step should print the values for the variables ID, Name, Actlevel, and Fee in the new data set. However, the SAS keyword print is misspelled in the PROC PRINT statement.

data sasuser.admitfee; 
   set sasuser.admit; 
run; 
proc prin data=sasuser.admitfee; 
   var id name actlevel fee; 
run;

When the program is submitted, messages in the Log window indicate that the procedure PRIN was not found and that SAS stopped processing the PROC step because of errors. No output is produced by the PRINT procedure, because the second step fails to execute.

In addition to correcting spelling mistakes, you might need to resolve other common syntax errors such as these:

You might also need to correct a semantic error such as this: